1. Field of the Invention
This invention relates to a slide fastener slider which, after a slider body has been assembled, a pull tab is attached to the slider body and is prevented from accidental removal.
2. Description of the Related Art
Many slide fastener sliders of the above-mentioned type are currently known. For example, Japanese Patent Publication No. Hei 1-14761 discloses a free-type slider which has a cantilevered arch-shape attachment lug integrally standing on an upper wing of a slider body at its front end and extending toward its rear end for holding an axle of a pull tab between the attachment lug and the upper wing, a recess formed in the upper surface of the upper wing in confronting relation to the rear end of the attachment lug for passage of the axle of the pull tab, and a resilient member supported by the slider body or the attachment lug for normally closing a gap between the upper wing and the rear end of the attachment lug. In production, for attaching the pull tab to the slider body, the resilient member is deformed by the axle of the pull tab so as to allow the axle to pass through the gap. Thus, the pull tab can be attached or detached freely
Japanese Utility Model Publication No. Hei 4-32974 discloses an auto-lock slide fastener slider which has, as shown in FIG. 10 of the accompanying drawings of the present specification, an arch-shape pull-tab holder 20' pivotally mounted at its front end on an attachment lug 10' standing on the upper end of a guide post 5' and extends toward the rear end of an upper wing 3', and a locking lever 35' pivotally mounted on the attachment lug 10' at a position towards the guide post 5' with its rear end, i.e. a locking pawl 36', inserted in a locking-pawl-insertion hole 28' of the upper wing 3' and with its front end touching a spring 26' received in a small vertical hole in the guide post 5', the locking lever 35' having on its upper side a rearwardly opening recess 41' in which the axle of a pull tab is to be received to actuate the locking lever 35'. The rear end of the pull-tab holder 20' defines with the upper wing 3' a gap for passage of the axle of the pull tab. A gap-closing member 50' is slidably supported on the upper wing 3' for movement between a gap-closing position and a gap-opening position towards the guide post 5'. By pushing the gap-closing member 50' away from the gap by the axle, the pull tab can be threaded onto and removed off the pull-tab holder 20' via the gap.
Republic Chinese Patent No. 264642 discloses a slide fastener slider with an automatic locking mechanism which has, as shown in FIG. 11 of the accompanying drawings of the present specification, a cantilevered arch-shape attachment lug 10" standing on the upper wing 3" at its rear end and extending toward its front end, i.e. the upper end of a guide post 5", so as to define between a downwardly bent front end of the attachment lug 10" and the upper surface of the guide post 5" a gap for passage of an axle of a pull tab, a spring 26" received in a first vertical through-hole 16"-1 of the guide post, a gap-closing member 50" supported on the upper end of the spring 26" and normally urged against a lower surface of the front end of the attachment lug 10' for closing the gap 14", a second vertical through-hole 16'-2 extending in the front end of the attachment lug in alignment with the first vertical through-hole 16"-1, a horizontal lockinglever-attaching hole 42" perpendicularly crossing the second vertical through-hole 16"-2 in the front end of the attachment lug 10", a resilient locking lever 35" received in the locking-lever-attaching hole 42" with its rear end, e.g. a locking pawl 36", inserted in a locking-pawl-insertion hole 28" of the upper wing 3' to retractably project into a guide channel 7" of the slider body 1", and a locking-lever-anchoring strip 60' inserted in a slot 43" of the base of the locking lever to secure the locking lever 35". By pushing the gap-closing member 50" downwardly off the front end of the attachment lug 10" by the axle, the pull tab can be threaded onto the attachment lug 10" via the gap 14".
However, in the slider disclosed the first-named publication, partly since the pulling force of the pull tab acts directly on the resilient member and partly since the resilient member is supported in the attachment lug, a stable pull-tab-catching mechanism cannot be achieved. Further, since the pull-tab attaching and detaching mechanism and the pull-tab holding mechanism are complex, it is difficult to achieve a simple assembling of the slider, thus the resulting slider is not suitable for an automated assembling process.
In the auto-lock slider shown in FIG. 10 and disclosed in the second-named publication, due to its complicated structure, it is difficult to take appropriate adjustments for smooth actuation and operation. Also, since either the automatic locking mechanism or the gap-closing mechanism is composed of a rather large number of parts, efficient assembling is difficult to achieve and, as a consequence, this prior art slider is not suitable for automated assembling. Furthermore, this slider is necessarily large in height due to its peculiar structure, can not be made flat in structure and hence not neat in appearance.
Also in the auto-lock slider shown in FIG. 11 and disclosed in the third-named publication, it is difficult to assemble the automatic locking mechanism and the pull-tab-removal preventing mechanism in a streamlined process on an automatic assembling machine. As a consequence, this prior art slider is not suitable for automated assembling. Further, after the pull tab has been attached to the slider body, the axle of the pull tab comes directly into contact with the gap-closing member 50" and might therefore fail to actuate the locking lever 35" so as to retract the locking pawl 36" off the fastener element rows.